For any locals, I'm from the San Francisco Bay Area, so my views reflect my expectations there. I wasn't entirely sure what to expect on my first visit to "Gian' iggle", but there weren't too many surprises. It's pretty similar to Safeway or Lucky's. That is, a huge amount of processed food, and a passable produce section.
The produce was similar to what you'd see in California this time of year, maybe a touch more limited. Also, it was holiday season, so all the junk that's associated with that too.
The obvious differences were no alcohol section at all - you can wander down the strip mall to the "Beer" store and buy mostly only in 24 packs. Apparently some of the Giant Eagles sell six packs, but not this one. Also for people from out of state, check out the pierogi section, and the chipped ham, and other Pittsburgh oddities.
For a vegan, this is easy enough - lots of produce, and all the things you'd find in any other large chain.